The invention relates generally to imaging systems. In particular, the invention relates to a detector array for use in an imaging system and a method of making the same.
Detector arrays are used in a wide variety of imaging systems, such as computed tomography (CT), x-ray, and other radiation-based imaging systems. In operation, these imaging systems pass radiation through a subject and, after being attenuated by internal features of the subject, the radiation strikes pixelated scintillators. The scintillator material of these pixelated scintillators creates light in response to the received radiation. In other words, the intensity of the radiation received at the pixelated scintillators is generally dependent upon the attenuation of the radiation by the subject. Moreover, each pixel of the pixelated scintillator is separately illuminated in response to the attenuated beam received by the respective pixel of the pixelated scintillator. In this manner, these separately illuminated pixels of the pixelated scintillators facilitate the generation of an image of the internal features of the subject.
In radiation-based imaging systems, various features cooperate with the pixelated scintillators to create the desired image. In CT imaging systems, the x-ray source and the detector array are rotated within an imaging plane about the gantry surrounding the subject. X-ray sources typically include x-ray tubes, which emit the x-ray beam directed at a focal point. The CT imaging systems also generally include a collimator for collimating x-ray beams directed toward the pixelated scintillators. As noted above, the pixelated scintillators include a scintillator material that converts the x-ray radiation into light. Each illuminated pixel of the pixelated scintillator is detected by a respective photodiode, which converts the light into electrical signals used for imaging purposes. During data collection, each pixel provides an electrical output signal representative of the light intensity present in that pixel of the pixelated scintillator. These output signals are then processed to create an image of the internal features of the subject.
In imaging systems for medical and other diagnostic applications, an ongoing goal is the development of a low-cost, high quality, high resolution imaging system for an opaque target. In order to achieve high-resolution images in CT detectors, it is desired to have a pixelated scintillator having a large number of individual pixels. Ideally, each pixel is dimensionally equivalent throughout the pixelated scintillator. Existing manufacturing techniques for making these pixelated scintillators or other structures having parallel members, such as heat sinks, sensors arrays, lasers, radiative heaters, parallel plate capacitors, and the like, may involve dicing the material into small pieces and manually assembling them into a structure with a desired geometry prior to attachment to a device/system. This process is very tedious, costly, and prone to errors. Also, the pixels formed by this process have a relatively limited shape, depth, and other features. In case of pixelated scintillator, in an alternative technique, the pixelated scintillator is formed by ablating regions of the scintillator material using laser beams or electromagnetic radiations. However, this latter technique is relatively expensive and demonstrates marginal performance.
Accordingly, a need exists for a relatively fast, precise, and low cost technique for fabricating pixelated structures, such as pixelated scintillator arrays, for use in various systems.